This is a renewal for years 11-15 to complete the Hutchinson Smoking Prevention Project, an ongoing, statewide, Phase IV, 15-year randomized trial in school-based tobacco use prevention. The continuing objective of the trial is to rigorously test in a realistic setting the effectiveness, cost-effectiveness, and practicality of a multicomponent, school-based, grade 3-12 tobacco (smoking and smokeless tobacco use) prevention intervention in reducing long-term (2 years after high school) tobacco use prevalence. The intervention includes both prevention and cessation components for both classroom and school-wide implementation. Begun in 1984, HSPP is a peer-reviewed and funded part of the NCI's Smoking, Tobacco, and Cancer Program. The study population of 8,388 children in 40 geographically and demographically diverse school districts in Washington started the study as 3rd graders, and is now in high school. With the school district as the experimental unit, two consecutive cohorts in each of 20 experimental and 20 control school districts are being followed for collection of outcome data at the end of high school (grade 12) and two years beyond (Plus-2). Specific activities in years 11-15 are those needed to take this trial to its successful completion: the collection and evaluation of outcome data at grade 12, and the tracking of study participants, and collection and evaluation of main endpoint data at two years after high school. Trial results are scheduled to be released for grade 12 at the end of year 13, and for the Plus-2 endpoint at the end of year 15. With its 40 collaborating school districts statewide, its theory-based intervention that spans virtually the entire period of adolescent smoking onset, and follow-up into young adulthood, the HSPP trial is the most comprehensive test of school-based tobacco prevention ever conducted. If this trial continues on schedule and as designed, it will be completed in years 11-15 and will yield the following products: (1) an innovative, state-of-the-art, realistic, grade 3-12, multicomponent, school-based tobacco use prevention/cessation intervention ready for dissemination; (2) a rigorous evaluation of the intervention's long-term effectiveness, cost- effectiveness, and practicality; (3) a plan for national dissemination in the event of positive long-term intervention effects; (4) documented methodology for addressing challenges inherent in disease prevention trials; and (5) characterization of those study participants for whom the intervention failed to deter regular tobacco use at Plus 2. In addition, HSPP is the vehicle for the separately funded Ripple Effects adjunct study (years 09-13) that will yield an evaluation of the extent to which the impact of the HSPP intervention extends beyond the study participants to their parents and to the administrators and staff of their schools.